Fullstack Software Engineer - Business Solutions

About UsAt Lightning AI, we are the pioneers behind PyTorch Lightning, established in 2019. Our mission is to create a seamless end-to-end platform that simplifies the development, training, and deployment of AI systems, effectively bridging the gap between research and production.Following our merger with Voltage Park, an innovative neocloud and AI Factory, we deliver developer-centric software integrated with cost-efficient, large-scale computing. Our solutions empower teams with essential tools for experimentation, training, and production inference while ensuring robust security, observability, and control.We cater to a diverse clientele, including independent researchers, startups, and major enterprises. With global operations and offices located in New York City, San Francisco, Seattle, and London, we are backed by prestigious investors such as Coatue, Index Ventures, Bain Capital Ventures, and Firstminute.

Who We AreLightning AI is the innovative force behind PyTorch Lightning, established in 2019. We provide a comprehensive platform designed to streamline the development, training, and deployment of AI systems, effectively bridging the gap between research and production.Our merger with Voltage Park, a neocloud and AI Factory, empowers us to combine developer-centric software solutions with economical, large-scale computing capabilities. We equip teams with essential tools for experimentation, training, and production inference, ensuring built-in security, observability, and control.We cater to solo researchers, startups, and large enterprises alike, operating globally with offices in cities such as New York City, San Francisco, Seattle, and London. Our efforts are supported by notable investors including Coatue, Index Ventures, Bain Capital Ventures, and Firstminute.What We’re Looking ForWe are seeking a skilled Backend Engineer to develop and enhance the Lightning AI platform across various components, from the frontend and CLI to API, billing, security, and integrations. You will take full ownership of key features, driving development from concept to production while collaborating with a talented team of engineers, product managers, and designers. This role offers the chance to create groundbreaking technology that will revolutionize the machine-learning ecosystem!This hybrid position is based in our London office with a requirement of 2 in-office days per week. The salary range for this role is $120,000 - $250,000.

About UsLightning AI, the driving force behind PyTorch Lightning, was established in 2019. Our mission is to create a seamless, end-to-end platform that simplifies the development, training, and deployment of AI systems, allowing innovative ideas to transition smoothly from research to production.Following our merger with Voltage Park—an AI Factory and neocloud—Lightning AI merges developer-centric software with efficient, large-scale computation. Our platform provides teams with the essential tools for experimentation, training, and production inference, all while ensuring security, observability, and control.We cater to a diverse clientele, including individual researchers, startups, and major enterprises. With a global presence and offices in New York City, San Francisco, Seattle, and London, Lightning AI is supported by esteemed investors such as Coatue, Index Ventures, Bain Capital Ventures, and Firstminute.Our Core ValuesMove Fast: We prioritize speed and precision, breaking down complex challenges into manageable tasks.Focus: We dedicate ourselves to completing one goal at a time, collaborating effectively to deliver precise features.Balance: We believe sustained performance results from adequate rest and recovery, promoting a healthy work-life balance.Craftsmanship: Innovation through excellence—every detail counts, and we take pride in honing our craft.Minimal: We embrace simplicity as a driver of innovation, focusing on what truly matters.Your RoleWe are seeking a skilled Frontend Engineer to enhance and scale the UI and frontend infrastructure of the Lightning AI platform.In this role, you will take ownership of crucial features, driving development from concept to completion while collaborating with a talented team of engineers, product managers, and designers. Your work will focus on ensuring speed, quality, and rapid iteration—from initial proof of concept to final release.With over 10,000 organizations utilizing Lightning AI, this position offers you a unique opportunity to influence how AI solutions are built and deployed in production environments.You will be part of the Growth Squad and report directly to our Director of Engineering. This hybrid role is based in our London office, requiring in-office attendance for 2 days each week.

Join us as a Senior AI FullStack Engineer at a rapidly expanding AI FinTech company, where your expertise will help shape the future of finance.About Us:We develop and deploy AI-powered tools and intelligent agents throughout their entire lifecycle, from conception to production.Our systems are designed with AI at their core, not as an afterthought.Transform experimental concepts into production-ready features that impact real users.Take ownership of projects from problem identification to user adoption.Collaborate closely with engineering and product teams to seamlessly integrate AI into daily operations.Establish effective methodologies for implementing AI in production environments.We are on a mission to create an AI-native bank tailored for ambitious businesses.Your Contribution:Train and refine large-scale audio and multimodal models.Design and execute experiments focused on architecture, data mixtures, and training strategies.Develop and enhance audio data pipelines.Optimize inference speed, latency, and overall production readiness.Deploy models in end-to-end, low-latency settings.Create meaningful evaluation metrics that go beyond standard benchmark scores.Work collaboratively with both research and engineering teams.This role is hands-on, bridging the gap between research and real-world application.Technical Environment:PythonLarge Language Models (LLMs) and AI toolsPostgreSQL, BigQueryTypeScript, ReactAWS, GCPDocker, Terraform, GitHub(Detailed technical stack will be shared during the interview process)Your Expertise:5+ years of experience in building and deploying production systems.Full-stack or deep backend/platform engineering skills.AI-native mindset: you leverage AI in your daily work and think in terms of agents, workflows, and automation.Product-focused: your priority is user adoption over mere output.You excel at transforming complex challenges into scalable solutions.Bonus Skills:Experience in financial technology.Familiarity with cloud services and infrastructure.Contributions to open-source projects.

Join Contentsquare, a pioneering experience intelligence platform, where we empower organizations to gain deep insights into their customers' digital journeys. Our innovative and scalable platform is designed for users across various expertise levels, making it easier to navigate the complexities of online interactions.As a global leader in experience analytics, we operate from 15 offices worldwide, committed to making a significant impact in the industry. We are seeking enthusiastic team members who are ready to contribute to our growth and success.At Contentsquare, we foster an inclusive work environment where every individual can thrive. Our community is built on values of courage, empathy, and intentionality, aimed at simplifying challenges for our clients, their customers, and each other.Note: Please be cautious of scam attempts impersonating Contentsquare. We do not request money or communicate through unsolicited messages. For further details, check our careers blog.Important Information:1. This is a software engineering position requiring a minimum of 5 years of relevant experience, particularly in TypeScript. While we utilize Large Language Models (LLMs), this is not a machine learning-focused role.2. The role is available as remote (in France, Spain, Italy, Poland, or Germany) or can be hybrid in our offices located in Barcelona, Paris, Milan, Munich, or Cairo.We are on the lookout for a Senior Fullstack Engineer (Applied AI) to engage in various innovative projects that harness the power of AI, especially leveraging LLMs. One of the key initiatives involves enhancing our AI CoPilot tool (currently exclusive to Heap) to broaden its application, allowing users with no prior experience in product or digital experience analytics to easily find answers through simple inquiries.Our rapid advancement in utilizing LLMs aims to streamline insights generation and simplify setup processes, among other enhancements. As our next Senior Software Engineer (Applied AI), you will play a significant role in product development and initial product iterations, participating in user interviews to validate product hypotheses.This position offers a unique opportunity to operate within a “startup-like” environment, where we swiftly transition from concept to proof of value, ensuring that our solutions deliver real benefits to our clients.

Founded in 2018, Causaly is at the forefront of transforming enterprise-scale scientific research through our innovative AI platform. Our technology empowers researchers to efficiently discover, visualize, and interpret biomedical knowledge, streamlining critical research workflows to tackle some of the most pressing health challenges of our time.We partner with leading biopharma companies and institutions, focusing on diverse use cases including Drug Discovery, Safety, and Competitive Intelligence. Visit our blog to learn how we enhance knowledge acquisition and decision-making: Blog - CausalyCausaly is proudly backed by renowned venture capital firms, including ICONIQ, Index Ventures, Pentech, and Marathon.

Role Overview hook is hiring a Backend / Fullstack Engineer in London. This role involves building server-side applications and contributing to front-end features that improve how users interact with our products. What You Will Do Develop and maintain backend systems Work on front-end components to support a seamless user experience Participate in the full software development lifecycle, from initial idea through deployment Who We’re Looking For Comfortable working with both backend and frontend technologies Interested in taking projects from concept to launch Ready to collaborate with a team in London

Join Our Engineering TeamAt CoreWeave, we are revolutionizing the AI landscape. Our Monolith AI Engineering Team is dedicated to constructing and enhancing the foundational platform that drives the most sophisticated engineering simulations and AI workflows. Our mission is to transform into the super-intelligent AI test lab for the engineering sector, empowering our clients to "ship science, faster." We focus on advancing distributed architecture and facilitating the next wave of agentic interfaces and physical AI, providing the reliable and scalable infrastructure that the world’s leading engineering firms depend on.Your RoleWe are seeking a talented Fullstack Engineer with a Frontend Focus. You will take charge of the Monolith platform’s product surface, which offers a data-rich, workflow-centric web interface where engineers can design experiments, compare outcomes, interact with agents, and convert intricate physical test data into actionable insights. Your collaboration with Design, Product, and Backend Engineering teams will be crucial in delivering a UI and UX that is fast, intuitive, and dependable for non-ML expert engineers. Additionally, you will contribute to our Python backend services as needed.Position OverviewThis is an IC5 Fullstack Staff Engineer role with a significant emphasis on frontend development (approximately 80–90%). We are also open to exceptional candidates for the Senior Fullstack Engineer II (IC4) level who can perform at a staff-like capacity. You will be responsible for the Monolith web application, focusing on component architecture, design system evolution, performance, and user experience for complex, data-rich workflows. You will also engage with our Python services (FastAPI/Flask) to shape and integrate APIs and implement new platform capabilities, enhancing user experiences.

Lightning AI builds tools that help researchers and organizations bring AI projects from idea to production. Known for PyTorch Lightning, the team focuses on making it easier to develop, train, and deploy AI systems. Since merging with Voltage Park, Lightning AI combines developer-focused software with scalable compute resources. The platform supports experimentation, training, and production inference, while emphasizing security and control. Offices are located in London, New York City, San Francisco, and Seattle. Investors include Coatue, Index Ventures, Bain Capital Ventures, and Firstminute. Values Move Fast: Break big challenges into achievable tasks and act quickly. Focus: Work as one team to deliver well-crafted features, concentrating on a single goal at a time. Balance: Support healthy work habits and value rest for long-term results. Craftsmanship: Aim for excellence and innovation, paying close attention to detail. Minimal: Keep solutions simple and disciplined, avoiding unnecessary complexity. Role overview This hybrid Research Engineer position is based in London. The role centers on optimizing training and inference workloads on compute accelerators and clusters, with a focus on the Lightning Thunder compiler and the PyTorch Lightning ecosystem. Work will blend deep learning research, compiler development, and large-scale system optimization. The Research Engineer will help build foundational software that improves model performance and efficiency, shaping the future of machine learning infrastructure. This position reports directly to the Tech Lead and is part of the Engineering Team. Flexible work options are available.

Join Octopus Energy, a pioneering force in the renewable energy sector, where we are redefining how energy is supplied in Britain. Our mission is to create a fully digital energy experience that empowers our customers while promoting sustainability. With a unique blend of innovative technology and a dedicated team, we have already become the largest energy supplier in the UK. As we expand, we are committed to accelerating the green energy transition through cutting-edge products and services that simplify the switch to renewable solutions such as heat pumps, solar power, and electric vehicles. At Octopus Tech, you will have the opportunity to take ownership of meaningful projects that positively impact lives—by reducing energy costs and enabling eco-friendly living. Collaborating with cross-functional teams, you will witness the immediate results of your work in the real world. As we build a lean and effective TechOps Engineering team, we seek a talented and experienced Full Stack Software Engineer to contribute to our vision. You will play a vital role in shaping the TechOps function, developing self-service technology that enhances our team's ability to leverage advanced tech solutions. TechOps represents a modernized approach to traditional IT, encompassing everything from first-line support to strategic planning. We are looking for someone who will help design and implement efficient, scalable, and robust solutions for our TechOps capabilities. If you are excited about making a difference in the renewable energy landscape, we would love to hear from you!

At Coram AI, we are revolutionizing video security in today's digital landscape. Our innovative cloud-native platform leverages cutting-edge computer vision and artificial intelligence to empower businesses with enhanced safety, informed decision-making, and rapid response capabilities. Experience real-time alerts, effortless clip sharing, and comprehensive visibility across multiple sites.Joining our dynamic, agile team means embracing clarity, excellence, and impactful contributions. Every team member has a voice, delivers significant work, and plays a vital role in shaping how AI can foster a safer and more interconnected world.In this role, you will be part of a pioneering team responsible for managing a sophisticated infrastructure that transcends conventional cloud setups. Beyond our robust AWS and Kubernetes configurations, we also oversee a vast array of IoT devices. We are in search of a skilled engineer who will play a crucial role in developing and maintaining our edge and cloud stack that supports our IoT product offerings, focusing on both infrastructure and the bespoke software we utilize.You will tackle intriguing challenges at the confluence of user experience, machine learning, and infrastructure, while committing to excellence, continuous learning, and delivering exceptional products in a fast-paced startup environment.

lovable is looking for a Fullstack Enterprise Engineer in London. This position centers on building and delivering software solutions that meet enterprise standards. Collaboration with teams across disciplines is a key part of the work. Role overview This role involves developing software from both the front-end and back-end, ensuring each component integrates smoothly. The focus is on producing reliable, maintainable code that supports business needs. What you will do Develop and implement software solutions for enterprise use Work with cross-functional teams to deliver projects Apply experience in both front-end and back-end technologies Requirements Experience with front-end and back-end development Ability to collaborate effectively with colleagues from different specialties Commitment to producing high-quality, impactful results

About Lightning AIFounded in 2019, Lightning AI is the driving force behind PyTorch Lightning. We create a comprehensive platform for the development, training, and deployment of AI systems, streamlining the journey from innovative research to impactful production.Our merger with Voltage Park, a neocloud and AI factory, enhances our offerings by integrating developer-centric software with efficient, large-scale computing resources. We provide teams with essential tools for experimentation, training, and production inference, ensuring security, observability, and control are integral to our solutions.We cater to individual researchers, startups, and established enterprises, with a global presence including offices in New York City, San Francisco, Seattle, and London. Lightning AI is supported by esteemed investors such as Coatue, Index Ventures, Bain Capital Ventures, and Firstminute.Our ValuesMove Fast: We prioritize speed and precision, deconstructing complex challenges into manageable tasks.Focus: We tackle one objective at a time with care, working collaboratively to deliver features accurately.Balance: We believe in maintaining a healthy work-life balance, promoting sustained performance through rest and recovery.Craftsmanship: We strive for excellence and take pride in the details that contribute to our innovation.Minimal: We embrace simplicity in our innovations, focusing on what truly matters.Role OverviewWe are looking for an accomplished Research Engineer to enhance the optimization of training and inference workloads using compute accelerators and clusters, particularly through the Lightning Thunder compiler and the broader PyTorch Lightning ecosystem. This role exists at the intersection of deep learning research, compiler development, and large-scale system optimization. You will be instrumental in advancing technology that enhances model performance and efficiency, establishing essential software that will influence the entire machine learning landscape.As part of the Engineering Team, you will report to our Tech Lead. This hybrid role is based in our offices located in New York City, San Francisco, or London.

Join StackOne:At StackOne, we are pioneering the future of SaaS and AI integrations. Supported by GV and Workday Ventures with $24M in funding, we empower developers of SaaS platforms and AI Agents to seamlessly integrate with a multitude of tools, enhancing functionality with scalable and precise solutions. Our platform boasts 25,000 pre-mapped actions across 200 connectors, alongside an AI-driven integration development toolkit that emphasizes security: featuring real-time architecture, managed authentication, and comprehensive observability.Join us on our ambitious journey towards revolutionizing agentic integrations.With an AI-native integration toolkit that ensures real-time execution and robust security measures, we are heavily investing in AI R&D. Our new lab focuses on developing specialized LLMs that excel in precision, reliability, and safety - crucial components for effective agentic execution.Your Role:As an AI Engineer, you will play a pivotal role in enabling users to integrate their preferred tools effortlessly with just one click, thanks to StackOne's innovative solutions.We seek a skilled Software Engineer with a solid foundation in AI production-grade applications, particularly with experience in working with LLMs (e.g., GPT, Anthropic, etc.).In this position, you will be responsible for delivering AI features and products throughout their lifecycle, collaborating closely with our dedicated AI team, which includes both AI researchers and engineers. You will report directly to the CTO.

Join Our Team as a Senior/Staff Fullstack Software Engineer!Location: Fitzrovia, London (Hybrid – 4 days in-office, 1 day remote)About Wizeline:Wizeline is a pioneering global technology solutions provider that harnesses the power of AI to craft innovative digital products and platforms. Our partnerships with clients enable us to leverage data and AI to expedite market entry and catalyze business transformation. Within our vibrant community of innovators, we cultivate a culture that prioritizes growth, collaboration, and impact.At Wizeline, we believe that with the right people and ideas, there are no limits to our achievements.Are You the Right Fit?If you are excited about technology and innovation, we want to hear from you! We are seeking a Senior or Staff Fullstack Software Engineer to contribute to pivotal projects for our esteemed client in London. In this role, you will be responsible for developing scalable, high-performance services that power the next-generation financial platform, which includes applications for deal execution, invoicing, payment distribution, and financial reporting. You will play an essential role in architecting backend systems, integrating with external platforms, and delivering features that streamline complex revenue and transaction workflows throughout the organization.This position operates under a hybrid work model based in Fitzrovia (London), requiring four (4) days in-office and one (1) day remote.Key Responsibilities:Design and implement services to support revenue workflows, payment logic, and invoicing pipelines.Develop robust APIs and full-stack features, utilizing type-safe ORM tooling for schema management and query composition.Manage integration with internal systems (e.g., Salesforce, NetSuite) and external providers (e.g., banks, payment processors).Implement structured financial logic including contingent payments, commission calculations, and milestone-based billing.Incorporate AI/LLM capabilities using Claude (Anthropic) and utilize Cursor as a core development tool to enhance delivery speed.Build and deploy infrastructure in AWS.Translate complex business rules into deterministic backend logic including commissions, milestones, payee splits, and contingent payments.Implement robust data flows between Client Processing, Deal Management, and Authoritative Data domains.

Join our dynamic team at minderacraft as a Staff Full-Stack Engineer. In this pivotal role, you will take charge of both backend and frontend development, crafting high-quality, scalable solutions while establishing engineering standards for the team. This position offers a unique blend of hands-on development and technical leadership, where you will mentor fellow engineers and collaborate closely with our product and platform teams.Your expertise will be crucial as you work with cutting-edge backend services developed in Kotlin, alongside rich frontend applications built with React and Next.js, utilizing TypeScript. Additionally, you will engage with cloud-native infrastructure on either Azure or AWS.This position is offered as an initial 6-month contract (outside IR35) with a requirement to be onsite in London Paddington three days a week.

About WexlerWexler is at the forefront of developing a revolutionary AI system tailored for litigation. We collaborate with some of the largest law firms globally, assisting them in navigating their most intricate legal battles, uncovering winning strategies, and transforming the overwhelming influx of documents and facts into actionable insights. Located in London, Wexler is a rapidly expanding legal AI company trusted by renowned firms such as Clifford Chance, HSFKramer, Goodwin, and Addleshaw Goddard to pinpoint crucial facts that can sway case outcomes.Backed by a $5.3M Seed round from Pear VC, Seedcamp, The LegalTechFund, and a host of esteemed industry angels, we are developing a comprehensive AI platform aimed at managing, resolving, and preventing legal disputes for Enterprise law firms and Fortune 500 companies. Our growth trajectory is remarkable, boasting a 10x year-over-year increase and onboarding more distinguished firms each month. Our innovative system efficiently extracts and cross-references facts from millions of documents, empowering litigators to secure more victories while significantly reducing the time spent on case preparation. Ultimately, we ensure that every client receives the legal representation they rightfully deserve.As AI reshapes the legal landscape, most existing tools have concentrated on contract law or serve as generic copilots across various legal tasks. In contrast, Wexler stands out as the premier generative AI platform meticulously designed for the intricacies of litigation, evidenced by our rapid growth and industry acceptance.About the RoleWe are in search of a talented AI Engineer to help redefine the future of legal practice. You will play a crucial role in building autonomous systems that analyze vast amounts of documents to extract pivotal factual information essential for winning legal cases. As an integral member of our team, you will have direct influence over our AI strategy, leveraging cutting-edge technology to address the real challenges faced by elite litigators.

Wise is seeking a Fullstack Engineer to focus on account setup features. This role centers on building and improving the systems that help customers create and manage their accounts smoothly. Role overview The Fullstack Engineer will work on both front-end and back-end components that support the account setup journey. Expect to collaborate closely with team members to identify pain points and deliver solutions that make onboarding easier for users. What you will do Develop and refine account setup processes to improve customer experience Work with engineers and other stakeholders to solve technical challenges Contribute to a collaborative team environment Requirements Experience working as a fullstack engineer Comfortable collaborating with others to solve problems Interest in building seamless, user-friendly account setup flows

Role Overview Legal & General is looking for a Senior Fullstack Software Engineer to help shape the future of our retirement services. This role focuses on designing and building software that supports and improves our products for customers in retirement. What You Will Do Develop and maintain software solutions across the stack to support retirement services Work closely with teams from different disciplines to deliver new features and improvements Contribute to technical decisions that raise the bar for quality and performance Focus on delivering reliable, maintainable code that enhances user experience Location This position is based in London.